Role of audiovisual synchrony in driving head orienting responses.
Role of audiovisual synchrony in driving head orienting responses.
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视听同步在驱动头部定向反应中的作用。
DOI：
10.1007/s00221-013-3522-4
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发表时间：
2013
影响因子：
2
通讯作者：
Ho C
中科院分区：
文献类型：
--
作者：
Ho C
现在许多研究表明，最佳的多感觉整合有时发生在听觉和视觉刺激异步呈现的条件下(即以100毫秒或更多的异步呈现)。这些观察结果表明，在呈现非同步(相比于同步)外围视听空间线索之后，参与者的快速定向反应可能会得到增强。在这里，我们报告了一系列旨在研究这一问题的三个实验。在确定双峰线索对其最佳单峰成分的有效性后(实验1)，被试必须做出朝向线索方向的快速转头或转向(车轮转动)反应(实验2)，或者做出远离线索的不相容反应(实验3)，以响应在刺激开始时呈现的随机外围视听刺激，范围从−100ms到100ms。结果(实验1)的种族模型不等性分析揭示了参与者转头和转向反应的多感觉易化的不同机制。在实验2和实验3中，成分听觉和视觉线索的同步呈现对参与者的反应潜伏期有最大的促进作用。有趣的是，当参与者必须主观判断视听刺激的同时性时，当听觉刺激落后视觉刺激22ms时，主观同时性就出现了。综上所述，这些结果似乎表明，当成分信号同步呈现时，由外围呈现的视听刺激产生的最大有益的行为(头部和手部)定向反应发生。这些发现表明，虽然大脑使用精确的时间同步来控制其定向反应，但人类大脑用来有意识地判断同步的系统似乎没有那么微调。
Many studies now suggest that optimal multisensory integration sometimes occurs under conditions where auditory and visual stimuli are presented asynchronously (i.e. at asynchronies of 100 ms or more). Such observations lead to the suggestion that participants’ speeded orienting responses might be enhanced following the presentation of asynchronous (as compared to synchronous) peripheral audiovisual spatial cues. Here, we report a series of three experiments designed to investigate this issue. Upon establishing the effectiveness of bimodal cuing over the best of its unimodal components (Experiment 1), participants had to make speeded head-turning or steering (wheel-turning) responses toward the cued direction (Experiment 2), or an incompatible response away from the cue (Experiment 3), in response to random peripheral audiovisual stimuli presented at stimulus onset asynchronies ranging from −100 to 100 ms. Race model inequality analysis of the results (Experiment 1) revealed different mechanisms underlying the observed multisensory facilitation of participants’ head-turning versus steering responses. In Experiments 2 and 3, the synchronous presentation of the component auditory and visual cues gave rise to the largest facilitation of participants’ response latencies. Intriguingly, when the participants had to subjectively judge the simultaneity of the audiovisual stimuli, the point of subjective simultaneity occurred when the auditory stimulus lagged behind the visual stimulus by 22 ms. Taken together, these results appear to suggest that the maximally beneficial behavioural (head and manual) orienting responses resulting from peripherally presented audiovisual stimuli occur when the component signals are presented in synchrony. These findings suggest that while the brain uses precise temporal synchrony in order to control its orienting responses, the system that the human brain uses to consciously judge synchrony appears to be less fine tuned.